1. Field of the Invention
The present invention relates to a waterproof sound-permeable membrane, a waterproof sound-permeable member, and an electronic device.
2. Description of Related Art
Electronic devices such as mobile phones, smartphones, laptop computers, electronic notebooks, digital cameras, and game consoles have an audio function. Inside the housing of an electronic device having an audio function, there is placed a sound transducer such as a speaker, buzzer, or microphone. The housing is provided with an opening for directing sound to the sound transducer from the outside of the housing and/or an opening for directing sound to the outside of the housing from the sound transducer. To prevent foreign matters such as water droplets from entering the housing, a waterproof sound-permeable membrane (which hereinafter may be simply referred to as a “sound-permeable membrane”) is attached to the opening of the housing.
JP 2007-81881 A states that a porous membrane of polytetrafluoroethylene (PTFE) can be used as a sound-permeable membrane. JP 4751476 B2 states that a non-porous film made of a resin such as PTFE, polyester, polycarbonate, polyethylene, or polyimide can be used as a sound-permeable membrane.